The invention relates to a perovskite of the ABO.sub.3 type provided with a surface layer. The perovskites are for example, SrTiO.sub.3, BaTiO.sub.3 or KNbO.sub.3. The invention also relates to a method of manufacturing such perovskites.
It is known to utilize perovskites as substrates for single crystal layer growth or as a material for high temperature fuel cells.
Perovskites have at their surfaces depressions or projections of a size corresponding about to their lattice parameter C=4 .ANG.. These deviations from a smooth surface detrimentally affect single crystal layer growth on the perovskites.
In addition, the life of a perovskite used in a high temperature fuel cell is limited because of the chemically aggressive environment.
It is the object of the present invention to provide a perovskite which is chemically more stable and is more suitable as a substrate for single crystal layer growth and to provide a method of manufacturing such perovskites.